A bale forming apparatus for agricultural purposes forms a round-cylindrical or cuboid bale in a bale forming chamber which is surrounded by a casing. After having formed the bale, the bale forming apparatus opens a discharge gate, e.g. a tailgate or a flap, of the casing and ejects the formed bale out of the casing. Several proposals how to do so have been made.
U.S. Pat. No. 7,331,279 B2 discloses a round baling press 10 which forms round-cylindrical bales 24 in a press chamber 22. A rear door 26 can pivot around a horizontal axis 28 with respect to the front housing. A hydraulic actuator 30 can pivot the rear door 26 upwards against the force of gravity such that a formed bale 24 can be ejected out of the press chamber 22. A sensor arrangement with three different sensors 38, 42, 44 can record the actual position of the rear door 26. The following position sensors are mentioned: A rotary potentiometer 38 records the rotational angle of the door 26 around the axis 28. An ultrasonic range sensor 42 measures the distance between the lower (outer) end of the rear door 26 and the ground. A flow sensor 44 measures the hydraulic fluid which flows into or out of the hydraulic chamber of the actuator 30. An electronic control 46 receives signals from the sensor arrangement 38, 42, 44. The electronic control 46 regulates the opening of the rear door 26 performed by the actuator 30. In one implementation the rear door 26 moves slowly at the beginning of the opening movement, relatively quickly in an intermediate phase, and again relatively slowly towards the end of the opening movement. In one implementation a bale size sensor 103 continuously senses the size of the bale 24. The actuator 30 opens the rear door 26 depending on the measured bale size.
EP 1444882 A2 discloses a round baler (Rundballenpresse) with a stationary front housing (Vordergehause 5) and a pivotal rear housing (Hintergehäuse 9). Thanks to a pivoting bearing (Schwenklager 8) the rear housing 9 can pivot with respect to the front housing 5. Two single acting hydraulic cylinders 14 can move the rear housing 9 with respect to the front housing 5 from a closed position 13 via an intermediate position 12 towards a fully open position 10. A control valve (Steuerventil 18) operates as a throttle valve and decelerates the rear housing 9 shortly before the moved rear housing 9 reaches the fully open position 10 or the fully closed position 13. In an alternative implementation two double acting hydraulic cylinders 23 are used. Two sensors 16, 17 measure the current position of the piston of the cylinder 13, i.e. the current stroke, and therefore a value indicative of the position of the rear housing 9. A control unit 33 receives signals from the sensors 16, 17. Depending on the sensor signals the control unit 33 decelerates the movement of the rear housing 9 by controlling a control valve 34. In one implementation the following further sensors are implemented: a rotary potentiometer (Drehpotentiometer 39) which measures the position of the rear housing 9 with respect to the front housing 5, a pressure sensor (Drucksensor 40) which measures the pressure of the hydraulic fluid in a line guiding to the rear housing actuator, a sensor 41 which detects the event that a severing device for severing a web of wrapping material is actuated, and a sensor 43 in a pivotal ramp (Ballenabrolleinrichtung 44) which detects the event that the round bale has left the pivoting area of the rear housing 9 and the situation that the rear housing 9 can be lowered downwards.
US 20150272007 A1 discloses a round baler with a bale chamber 26. An actuator assembly 32 can move the tailgate 30 from a closed position into an opened position. The tailgate 30 moves along a path 50, cf. FIG. 2. A bale position sensor 40 is mounted at the free end of a bale ramp 38. The ejected bale 28 drops onto the ramp 38 and is guided away from the bale chamber 26 by the ramp 38. The ramp 38 can carry the bale 28 in a so-called cleared position in which the tailgate 30 can be closed again while the bale 28 is still on the ramp 38. The bale position sensor 40 detects the event that the ejected bale 28 has reached the end of the ramp 38 and is in the cleared position. This detection triggers the step that the tailgate 30 is closed again.
EP 1266563 A1 discloses a baler-wrapper combination with a round baler 1 and a wrapper 3. The round baler 1 forms a round bale 42 in a baler chamber 4 and ejects the formed bale. The ejected bale rolls over a chute device onto the wrapping table of the wrapper 3. In a first embodiment, cf. FIG. 1 to FIG. 3, the bale rolls over a first chute device 20 with two ramps 26 and a second chute device 21 onto the wrapping table. Hydraulic cylinders 31 can move the chute device 20 from a rest position 32, cf. FIG. 1, into a working position 22, cf. FIG. 3. The cylinders 31 are activated by a sensor 35 which detects the event that the discharge gate (rear housing 10) reaches a specific intermediate position when being opened. A feeler means 53 detects the event that the round bale 42 has reached an end position on the second chute device 21. A signal from this feeler means 53 triggers the step of closing again the rear housing 10. In a second embodiment shown in FIG. 8 and FIG. 9 a chute device 75 comprises a swivel arm arrangement 78 with forwardly directed arms 79 and a U-shaped stirrup 80. The stirrup 80 comprises rearwardly directed arms 81 which form a ramp 82 for guiding an ejected round bale 83. A control rod 87 connects the swivel arm arrangement 78 with the rear housing 88. A tension spring 89 tends to pull the stirrup 80 into a rest position 90 while the rear housing 88 is closed.